O-Carboran

The silacarborane analogue of C,C-dimethyl-o / o-carborane, closo-l]l-((C i]) -l]lSi[ fri [128270 8 ] h.3.s been reported (179). This o-sdacarborane, which has an icosahedral framework much like o-carborane and is reported to be stable to air and moisture, was obtained in low yield from the reaction of decaborane and bis (dimethyl amino)metbyl silane in refluxing benzene. 

A/,A/-Dimethyiimidazoiidine, 360 A/,A/ -Diaryiimidazoiidine, 360 2,3-Dihydro-1,3-benzothiazoie, 361 Diethylamine Adduct, 361 A/-Methoxy-A/-methyiamine Adduct, 362 o-Carborane, 362... 

Many novel cluster compounds have now been prepared in this way, including mixed metal clusters. Further routes involve the oxidative fusion of dicarbon metallacarborane anions to give dimetal tetracarbon clusters such as (103) and (104) O (jjg insertion of isonitriles into inetallaborane clusters to give monocarbon meiallacarboranes such as (105) and the reaction of small ii/t/o-carboranes with alane adducts such as Et3NAlH3 to give the commo species (106) ... 

Carboranes are also called o-carboranes, while the 1,7- and 1,12-isomers are m- and / -car-boranes respectively. Chemical Abstracts uses the sequence C-H-B-N (etc.) in the Formula Index, whereas inorganic textbooks prefer B - C - H - N. 

Many bis-chelate Pd11 complexes possessing a m-arrangcmcnt of the phosphinoalkylsilyl ligands have been synthesized,386-389 but comparatively few /ranx-bis-chelates are known. The kinetic stability of trans-bis-chelates can be greatly enhanced by placing a bulky o-carborane unit in the ligand backbone.390... 

Homoleptic gold(III) complexes with other related dithiolate ligands, as dmit (317),1855-1864 dddt,1865,1866 l,3,5-trithiepin-6,7-dithiolate,1867 dithiosquarate (318),1868,1869 6,7-dihydro-6-methy-lene-5H-l,4-dithiepine-2,3-dithiolate,1870 3,4-thiophenedithiolate (319),1637 quinoxaline-3,3-dithiolate (320),1871 2,2-diacetylethylene-1,1-dithiolate,1872 or o-carborane-1,2-dithiolate have been... 

Other [AuCIL] complexes with monophosphines are those derived of o-carborane (427),2506 pyr-anoside group (428),2507 a-dimethylamino(3)ferrocenophan-2-yl,2508 calix[4]arene derived phosphites,25 or aminoxyl radical-substituted phosphines (429),2510 for which ferromagnetic interactions have been observed. 

The addition of o-carborane to electrophiles is one of the most important reactions to synthesize carboranes containing organic functional groups. Lithiocarbo-ranes which are readily prepared from butylithium with carboranes are widely utilized for C—C bond formation involving various functional groups. Recently, Yamamoto and co-workers have developed addition reactions of lithio-,73... 

It is known that a carborane framework involves three-center two-electron bonding and is thus an elelctron-deficient cluster. Shatenshtein76 reported that the pKa value of the C—H proton of carborane is 23. Therefore, a proton attached to the carbon of o-carborane could be deprotonated easily by a weak base, and the resulting... 

Dehydrobenzene or benzyne 158 can be trapped by all manner of species. 1,2-Dehydro-o-carborane 159 has been shown to undergo many of the same reactions as its two-dimensional relative, 1,2-dehydrobenzene. Although dehydroaromatic molecules can be formed in a variety of ways, synthetic pathways to 1,2-dehydro-o-carborane are quite limited. An effective procedure reported so far78 first forms the dianion by deprotonation of o-carborane with 2 equiv. of butyllithium. Precipitated dilithium carborane is then treated with 1 equiv. of bromine at 0°C to form the soluble bromo anion 160. Thermolysis of 160 with anthracene, furan, and thiophene as substrates leads to the adducts 161-164.79 80 1,2-Dehydro-o-carborane reacts with norbomadiene to give both homo 2+4 and 2+2 addition, leading to three products 165-167, in a 7 1 ratio79. An acyclic diene, 2,3-dimethyl-... 

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